I get that more MP is better ends up being pure marketing. However I don’t understand why all cameras don’t bring 108 MP sensors or whatever. I’m confused.
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The high MP count in phones is compensating for not getting a lot of light in the lens due to them prioritizing small (thin) size rather than photo quality, and would rather put multiple lenses than a zoom lens for example
You can drive a nail with a pipe wrench, but a hammer would probably do the job better, right?
Same thing with technology, it’s a phone first but it happens to take photos. Something that’s purpose built to take photos is going to do a much better job because the hardware inside is optimized for photo taking not being a portable porn box.
A camera sensor is better if it collects more light.
The sensors in conventional cameras are huge compared to smartphone sensors.
Analogy: you have two windows in your house. One is a normal size divided into 12 panes and the other is ten times smaller. The one that’s ten times smaller has 108 individual panes. Which one can you see out of better?
Dedicated cameras with full-frame sensors are much larger than a cell phone sensor (remember something like an iPhone Pro has 3 sensors on the back, 1 per lens).
Smaller sensor means less light hitting it, which means for the same shutter speed (capture time) to get the same brightness you need to increase the ISO (noise). The main way to increase detail such that the high noise isn’t so bad looking, besides smoothing, is to increase the megapixel count (so the noise artifacts are smaller, and of course higher detail).
So, even though ~12MP is enough for an 8×10 print if you don’t crop, a cell phone needs much more than 12MP or else the image would be noisy or heavily smoothed.
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My Sony A7RIII has a 42.4MP camera with a full-frame (35.9 x 24 mm) sensor, which is an area of 861.6mm^2, so each MP has an area of **~20mm^2**.
My iPhone 15 Pro Max’s main camera is 48MP with a sensor size of 9.8 x 7.3mm (from what I could find), which is an area of 71.54mm^2, so each MP has an area of **~1.5mm^2**, which is <1/13^th the size of my Sony camera.
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As for why professional cameras rarely go over ~60MP, it’s because their processors aren’t fast enough. The reason the cameras most YouTubers use is only a 12MP Sony (A7S series) and not the higher megapixel count A7R series is that these cameras have rolling shutter and other issues which make the video not look as good. High MP count in RAW would also lead to very slow burst mode. You have stacked sensors which do a faster job, but they are reserved for the higher end models and even then it doesn’t fully solve the issue. The processors inside are also doing tons of stabilization and auto-focus (new ones incorporate AI auto-focus), so they aren’t reserved solely for faster capture time. This also is why they have a rolling shutter and only super expensive movie cameras have a global shutter (where the entire sensor is read at once, versus line by line).
Sensor size
Smartphones have small sensors mainly due to the limited space, because of this the size of the pixels is reduced, meaning that the ability to capture light is limited which can make it more susceptible to noise.
On the other hand a DSLR for example may not have as many megapixels as the smartphone but due to its larger sensor, it can have larger pixels which allow for light to be more accurately captured and hence reducing noise, which in turn generally leads to a better quality image.
A digital camera will have a sensor that it *much* larger than a phone.
A larger sensor means you can collect more light in less time. (a shorter exposure is required)
A small senor will require a longer exposure time. And longer exposure on a CCD sensor = more noise. More noise = grainy pictures.
The higher megapixel counts on cell phones is mostly just marketing wank. And since the sensors are so small, it’s much cheaper to cram more pixels onto them.
It’s really just a quantity vs quality issue.
First off, it’s a lie. Take the Samsung Galaxy S22 Ultra, in marketing, it takes a 108MP photo, but it ***does not have a true 108MP sensor.***
They use pixel binning to take a 108MP photo, which is, they take 4x 27MP photos in rapid succession and digitally stitch them together into a larger 108MP photo. This is not as effective as a regular photo as it means anything moving will become a blurry mess as the photo takes 4 times longer to take.
Secondly. phone cameras use tiny little lenses, which have optical compromises, whereas full on professional cameras often use lenses that cost more than the camera itself. Those huge lenses exist to give the best optical quality possible, among other features/capabilities not found on a tiny cell phone camera.
Explain like your five: it’s all about your cameras eye (sensor) the larger the eyeball the more it can see. Mp is only how well it can see in the sense that a young man can see better (high mp ) than an old man (low mp).
Also cameras have to do with how wide an eye can open. The same way a cat can see in the night because its eyes are nice and big and wide but we can’t see very well.
Lens quality plays a huge role in addition to the other points made here. Smartphone lenses have come a looooong way, but they’re still not as sharp as professional lenses created for standalone camera systems.
There is a lot that affects image quality.
One is amount of light. Smaller lenses can collect and focus less light, and because a camera is just a light detector, smaller cameras (or smaller lenses) will always be inherently limited.
The second is the quality of a lens. Lenses aren’t perfect- different colors focus differently. Objects near the edge of a photo focus differently. Large cameras use better lenses to minimize this. Cameras are limited in how complex the lenses can be due to size, and thus limit how much this can be corrected. Phones also need to be cheap so cut corners, nobody is going to pay $2000 for a phone for a lens, but people will definitely pay that for a dedicated pro camera.
The third is that pixel resolution doesn’t equal image detail. Because of lens imperfections, and because of physics (diffraction) light has a fundamental resolution beyond which smaller or more pixels will not provide any more detail. In fact, too many pixels can make noise more apparent in the image. Smaller lenses run into this physical limit much more quickly, as the resolution limit of light depends on the lens size.
Also, smaller pixels lead to less range of colors because the pixels have less electrons to carry signal, meaning you get less rich colors or poor performance in suboptimal lighting.
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